/**
 * #      1467
 * 名称   两个盒子中球的颜色数相同的概率
 * 链接   https://leetcode-cn.com/problems/probability-of-a-two-boxes-having-the-same-number-of-distinct-balls
 * 题解   [40](https://leetcode-cn.com/problems/probability-of-a-two-boxes-having-the-same-number-of-distinct-balls/solution)
 * 通过率 59.3%
 * 难道   困难
 */

